Work continues on lateral suppression. We have tested a number of subjects with both forward- and backward-masking procedures and we continue to find that suppression is asymmetric--greater in one ear than the other at the same signal frequency--although for some reason the differences are smaller than we had initially found. We have also begun measuring psychophysical tuning curves, looking for asymmetries and for local irregularities at different frequencies in a single ear. Lateral suppression is also being studied in the presence of and in the absence of a high-pass noise whose function is to simulate in a normal ear the most common form of hearing loss. Previous research had shown that people with true high-frequency losses also showed reduced or absent lateral suppression, and our preliminary results indicate that the high-pass noise produces the same result. It is possible that both outcomes stem from an interruption in the normal interactions between outer and inner hair cells, a possibility we intend to pursue.